Inside casing cutter



May 10, 1938.

C. P. WILSON INSIDE CASING CUTTER w @N @www2/U. 9 1 e, e n u n J .auf n @l F l." my

[N VEA/TOR CL V05 ,0. h//L 50N By Patented May 10, 1938 UNITED STATES PATENT OFFICE Claims.

My invention relates to devices adapted to be lowered into a well for the purpose of operation upon a pipe in the well.

My invention finds its most useful embodiment in a pipe cutter adapted to be lowered into a well to cut ofi a portion of a pipe which for any reason may be stuck in the Well so that the pipe cannot be pulled from the well in one piece.

It is an object of the invention to provide a U device of this character which is rugged in construction and positive in its operation.

It is an object of the invention to provide a device having a tool carrying head adapted to be supported at the lower end of a string of l5 pipe which is lowered into the well, there being a tool bit carried in the head and means operative by rotation of the head to feed the tool bit gradually outwardly toward the wall of the pipe `which is to be operated upon.

2o In pipe cutters of this general character it is known that the raising and lowering of the string of pipe to which the cutting device is attached has been employed for the purpose of feeding the cutting blade outwardly. Also, it is known that J5 spring devices have been employed for this purpose. The applicants device differs, however, in the provision of an automatic feeding means operative in response to the rotation of the cutter body to produce a gradual micrometric feeding of the cutting tool toward and into the wall of the pipe which is to be cut 01T.

It is accordingly an object of the invention to provide a pipe cutter of this character havn ing a cutter body which is connected to the lower end of a string of pipe so as to be rotated thereby, together with a member adapted to engage a stationary part in the well so as to be thereby held stationary, and a cutter feeding mechanism operative in response to the rotation of the cutter body relative to the stationary member to gradually feed the cutting bit toward the wall of the pipe to be cut.

It is a further object of the invention to pro- 45 `vide a pipe cutter of this character adapted to be lowered into the well to cutting position, to be there caused to engage the pipe to be cut at a point above the plane of the cut to be made, to be then operated so as to cut the pipe, and

5o to be then lifted through the well so as to raise the portion of the pipe which has been cut off,

or which cutting device may be releasedfrom engagement with the pipe and withdrawn from the well alone.

Further objects and advantages of the invention will be made evident throughout the iollowing part of the specification.

Referring to the drawing, which is for illustrative purposes only,

Fig. 1 is an elevational view of the preferred 5 embodiment of my invention in condition to be lowered into a pipe for operation.

Fig. 2 is a vertically sectioned view of the device showing the parts thereof in the positions which they assume during the cutting operation.

Fig. 3 is a section on a plane represented by the line 3-3 of Fig. 2.

Fig. 4 is a section taken as indicated by the line 4--4 of Fig. 2.

Fig. 5 is a section on a plane indicated by the 15 line 5--5 of Fig. 2.

In the tool shown in the drawing I provide a tool bit I0 carried by a body I'I adapted to be connected through a bar I2 and a tool joint I3 with a string of pipe by which the tool may be lowered into a pipe I4 in a well which is to be cut. Broadly speaking, the body II carries a mechanism I4a for feeding the bit I Il outwardly into engagement with the wall of the pipe `I4, and means which operates in response to rotation of the body II relative to the pipe I4 to actuate the mechanism I4a so that the bit Ill will be fed gradually outwardly. This actuating means includes an annular member I5 which is adapted` during the cutting operation to be held stationary, and means I6 are provided for the purpose of engaging a stationary part in the well, such, for example, as the pipe I4, and likewise for engaging the annular member I5 so that such annular member I5 will be held stationary while 35 the bar I2 andthe body II are rotated relative thereto to perform the cutting operation.

lThe body II comprises an upper cylindrical portion I'I, a lower portion I8, and a cap I9 of rounded form adapted to be held in place by means of a screw 20 and to cover screws 2I by which the lower body portion I8 is secured against the lower portion of the upper body portion I'I. The upper body portion I'I has a lateral or radial slot 23 in its lower end in which the tool bit 45 or cutter I0 is slidable. This slot connects with a cavity 24 in the lower end of the member I'I, which cavity is closed by the lower member I8 and contains therein a cam 25 of spiral form which is mounted on a lateral shaft 26 and is connected to a worm wheel 2l in such a manner that rotation of the worm Wheel 21 will rotate the cam through a complete cycle of operation. Extending upwardly from one side of the cavity 24 in the member Il is a shaft opening 28 car- 55 rying a shaft 33 which also forms a part of the mechanism I4a for feeding the bit I0 outwardly. The lower end of this shaft 33 rests in an opening or bearing 3I formed in the upper face of the lower member I8, and a worm screw 32 is formed on the shaft 30 in a position to engage the worm wheel 21. The upper end 33 of the shaft 35 is exposed in a cavity 34 formed in the upper face of the upper member' I1, and connected to this upper end 33 of the shaft 30 is a star wheel 35k adapted to be engaged by a single lug or tooth 35 carried by the annular member i5 which forms a part of or comprises the actuat-l ing means of the invention.

The annular member I5 has a downwardly extending wall 38 which conceals the cavi ty 34. On this downwardly extending wall 38 the single tooth or dog 36 is formed. In the lower part of the annular member I5 is an annular cavity 39 in which a thrust bearing 4I! is placed so as to bear against the upper face of the body I I. The upper part of the annular member I5 has a projection or clutch member 42 adapted to enter a companion recess or notch 43 in the lower end of a tubular member 44 which is vertically slidable 5 on the bar I2 above the annular member I5 and forms a part of the holding means I6 by which the annular member I5 is held stationary. A spring 45 disposed in a counterbore 46 in the lower end of the tubular member 44, as shown in Fig. 2, raises the tubular member 44 to the position in which it is shown in Fig. 1, wherein a clutch dog 41 on the upper end of a sleeve 48 will be engaged in a companion clutch recess 49 in the lower edge of the tool joint I3. The sleeve 48 is threaded at 5I to the upper end of the tubular member 44 so that it operates as a part of the tubular member 44 and provides a shoulder 52 for limiting the upward movement of a slip member 53 which is carried by the tubular member 44 and has the purpose of grabbing the pipe I4 so that the tubular member 44 will be held stationary during the cutting operation.

The slip member 53 is of tubular form and comprises several slips 55 which are connected at their upper ends to a cylindrical wall 56. These individual slips 55 are provided with helical teeth, or thread-form teeth, 51 adapted to be forced into engagement with the pipe I4 by the conical surface 58 of the tubular member 44 when the tubular member 44 is moved relatively upwardly within the slip member 53. The cylindrical wall 56 forming the upper part of the slip member 53 has an inwardly projecting shoulder or flange 60 with vertical notches 6I therein adapted to receive lugs 62 which project radially from the upper part of the tubular member 44 in a posivtion below the shoulder 52. When the notches 5I and the lugs E2 are in alignment, as shown in Figs. 2 and 5, the slip member 53 may move downwardly from the raised position in which it is shown in Fig. 1 to the lowered or expanded position in which it is shown in Fig. 2. When the slip member 53 is in its fully raised position, as shown in Fig. 1, it may be rotated relative to the tubular member 44 to carry the notches 6I out of alignment with the lugs 62, whereupon the shoulder 60 will rest upon the upper faces 65 oi' the lugs 62, thereby holding the slip member 53 in raised or inoperative position.

The operation of the tool may be conducted as follows. With the cam 25 in such position that a retracting spring 61 carried in a slot 68 in the body I I may hold the cutter tool or bit I0 in re'- tracted position, as shown in Fig. i, and with the slip member 53 in raised or inoperative position, as further shown in Fig. 1, the tool is lowered down into the well and into the pipe I4 by means of a string of drill pipe connected to the tool joint I3 in the customary manner. Bow springs 10 oi' customary form may be provided on the slip member 53 so that when the cutting position of the tool is reached, these bow springs 1U will tend to hold the slip member 53 from rotating so that the tubular member 44, by rotation of the drill pipe, may be caused to rotate within the slip member 53 to bring the lugs 62 into alignment with the notches 6 I, whereupon the tubular member 44 may be raised within the slip member 53, thereby expanding the slips 55 into engagement with the inner face of the pipe I4. The body II will be likewise raised so as to hold the clutch projection 42 of the annular member I5 in engagement with the companion notch 43 in the lower end of the tubular member 44, with the result that this tubular member 44, being anchored in the pipe I4, will hold the annular member I5 stationary. By rotating the string of drill pipe, the body II is then caused to rotate in forward direction, for example, right-hand or clockwise direction as indicated in Fig. 4 by an arrow 15. This will cause the star or ratchet wheel 35 to pass through a circle of rotation, and each time it passes the lug 36 carried by the annular member I5 the wheel member 35 will be turned one 1 tooth forwardly, thereby rotating the shaft 30 and the screw 32 which in turn will transmit slow rotation to the worm wheel 21 and thereby rotate the cam 25 forwardly so that this cam 25 will force the bit I0 slowly outwardly toward the pipe I4 as the bit I0 revolves around thel vertical axis of the tool.

It will be noted that the dog or clutch lug 41 on the upper end of the sleeve 48 is of such length that when the bar I2 and the body II are fully raised, as shown in Fig. 2, the lug 41 will be out oi' engagement with the notch 49, and the tool joint i3 may rotate the bar I2 and the body II while the tubular'member 44 remains stationary. The clutch lug 42 on the annular member I5, however, is of such length that it at no time disengages the notch 43 in the lower end of the tubular member 44, thereby keeping the lug 42 always in alignment with the notch 43.

After the pipe I4 has been cut, the tool may be lifted without disengaging the slips 55, thereby carrying the severed portion of the pipe I4 upwardly through the well to the surface of the ground. Should it be desired, however, to

disengage the tool from the pipe I4, the rota- ,l

tion of the body II may be continued until the shoulder 16 of the cam 25 passes the inner end of the bit I0, whereupon the spring 61 will force the bit I0 into retracted position, at which time the tool may be lowered so as to move the tubular member 44 downwardly through the slip member 53, thereby disengaging the slips 55 from the pipe I4. While the tubular member 44 is thus lowered relative to the slip member 53, it may be rotated so as to disalign the lugs 62, with the not-ches 6I to lock the slip member 53l in its relatively raised position, whereupon the tool may be withdrawn from the pipe I4 or it may be lowered to another position within the pipe I4 and another cutting operation performed.

Although I have herein shown and described my invention in simple and practical form, it is recognized that certain parts or elements thereof are representative of other parts, elements,

or mechanisms which may be used in substantially the same manner to accomplish substantially the same results; therefore, it is to be understood that the invention is not to be limited to the details disclosed herein but is to be accorded the full scope of the following claims.

I claim as my invention:

1. A pipe cutter of the character described for cutting oif a pipe in a well, including: a rotary member adapted to be connected to the lower end of a string of pipe; a cutter body connected to said rotary member so as to be rotated thereby; a cutter member supported in said cutter body in a position to be projected into engagement with the wall of the pipe to be cut; an actuating member carried by said rotary member in a manner allowing relative rotation of said rotary member without longitudinal movement of said actuating member; holding means for said actuating member operative to connect said actuating member to a stationary part in the well; a movable cam carried by said body in engagement with said cutter member and operable during a portion of its movement to apply force to said cutter member to move said cutter member into engagement with said pipe; means operable to retract said cutter member when the mentioned force is not applied thereto by said cam; and means operated by said actuating member when said rotary member is rotated relative to said actuating member to move said cam.

2. A pipe cutter of the character described for cutting 01T a pipe in a well, including: a rotary member adapted to be connected to the lower end of a string of pipe; a cutter body connected to the lower end of said rotary member; a cutter member supported in said cutter body in a position to be projected into engagement with the wall of the pipe to be cut; an actuating member on said rotary member above said cutter body and rotatable Without longitudinal movement relative to said rotary member; holding means rotatable and slidable on said rotary member above said actuating member, said holding means having slips for connecting it to a pipe in the well and having means at its lower end for preventing rotation of said actuating member when the same is raised intoy engagement with said holding means; a movable cam carried by said body in engagement with said cutter member and operable during a portion of its movement to apply force to said cutter member to move said cutter member into engagement with said pipe; means operable to retract said cutter member when the mentioned force is not applied thereto by said cam; and means operated by said actuating member when said rotary member is rotated relative to said actuating member to move said cam.

3. In a device of the character described, adapted to be lowered into a well for operation on a pipe therein, the combination of: a body adapted to be connected to the lower end of a string of pipe; an engagement member in rotatable relation to said body, said engagement member having means for engaging a stationary part in the well so that it will be thereby held from rotation; a projectable tool bit carried by said body; a rotary cam carried by said body having connection with said tool bit for feeding the same toward the wall of said pipe; an operating mechanism including a rotatable shaft operably associated with said body to be rotated thereby, and drive means associated with said shaft `and operable to rotate said cam through a cycle of its rotation in one direction in which it first moves said tool bit into engagement with said pipe and then allows said tool bit to be retracted away from said pipe; and means for retracting said tool bit.

4. In a device of the character described, adapted to be lowered into a well for operation on a pipe therein, the combination of a body adapted to be connected to the lower end of a string of pipe; an engagement member in rotatable relation to said body, said engagement member having means for engaging a stationary part in the well so that it will be thereby held from rotation; a projectable tool bit carried by said body; a rotary cam carried by said body having connection with said tool bit for feeding the same toward the wall of said pipe; shaft means mounted in said body, said shaft means having one end thereof presented toward said engagement member; gear means connecting said shaft means to said cam so that rotation of said shaft means will rotate said cam; and means operative in response to rotation of said body relative to said engagement member to rotate said shaft means.

5. In a device of the character described, adapted to be lowered into a well for operation on a pipe therein, the combination of: a bar adapted to be secured to the lower end of a string of pipe; a body secured to the lower end of said bar so as to rotate therewith; a tool bit carried by said body so as to be projected toward said pipe in said well to be operated upon; a cam carried by said body and by its movement projecting said tool bit; a shaft carried by said body, the upper end of said shaft being exposed; means between said shaft and Said cam whereby rotation of said shaft moves said cam; a ring on said bar adjacent the upper end of said body; a tubular member on said bar above said ring provided with means for engaging a pipe in the Well so that said tubular member will be thereby held stationary; clutch means operative between said tubular member and said ring for holding said ring stationary; a wheel member on the exposed end of said shaft; and means connected to said ring and having engagement with said wheel member to rotate the same and said shaft when said body is rotated relative to said ring.

CLYDE P. WILSON. 

